Environnements virtuels avec venv

Every project needs its own libraries. A virtual environment keeps each project's packages separate, so one app never breaks another. 🧳

Installing packages globally mixes versions across projects. One upgrade can suddenly break an older app that relied on the old version.

Python ships with venv, a built-in tool that creates an isolated folder holding its own Python and packages. No extra install needed.

Run one command to build a fresh environment. The venv folder appears in your project, ready to hold your packages.

You must activate the environment before using it. On macOS or Linux, source the activate script in your terminal.

On Windows the path differs slightly. The same activate step turns the environment on for your current shell session.

Once active, your prompt shows the environment name in parentheses. That little (venv) tag confirms you are isolated. ✅

With the environment active, anything you install with pip lands inside venv only, never touching your system Python.

Finished working? Run one word to leave the environment. deactivate returns your shell to the normal system Python.

The venv folder is large and machine-specific. Add it to .gitignore so it never gets committed to your repository.

Give every project its own environment. This isolation means each app pins exactly the versions it was built and tested against.

You learned to create, activate, and deactivate a venv, keeping each project's packages isolated and out of Git. Clean foundations! 🎉